The 2-Factor Storage Bar uses complex two factor authentication to access the stored BTC value once it is sent to the bar. These bars have their public address laser printed onto them, as well as ‘casascius.com/2factor’ which explains how the bars work. In order to redeem the bar, one must not only tear the hologram …

Full coin information →“Series 2 2011 ‘2FA Storage Bar’”

These bars were the first ‘empty’ item released by Casascius. They function like any physical Casascius coin in that bitcoin can be sent to it using the first-bits, but redeemed only by removing the hologram.

The 2FA 1,000 BTC bar is one of a kind. It has ‘ZERO BTC’ engraved on to the hologram. ‘2factor’ is also engraved on to the hologram. It is a rarer counterpart to the series 2 100 BTC ‘2FA’ bar.

These bars were created from 100 BTC bars that were not funded or sold. In order for Mr. Caldwell to confidently sell unfunded bars that were stamped with ‘100 BTC’, he came up with the idea to add a laser-engraved ‘ZERO BTC’ directly onto the hologram to make it clear that the intact hologram was …

Full coin information →“Series 2 100 BTC 2011 ‘2FA Unfunded Bar’”

These ‘Non-2FA’ 100 BTC bars are limited to a mintage of only eight pieces, none of which have been funded. To uniquely identify them as unfunded bars, these bars come with a ‘ZERO BTC’ etched hologram which is intentionally placed upside down. Additionally a small red dot was placed by the first-bits to further differentiate …

Full coin information →“Series 2 100 BTC 2011 ‘Unfunded Bar’”